The present invention relates to a dot point glazing apparatus for assembling glass plates into a glass screen.
Various types of glazing systems, such as the curtain wall system, the structural sealant glazing system, the dot point glazing system, etc., are used for assembling glass plates into a glass screen.
In the dot point glazing system, a dot point glazing apparatus engages holes made in the glass plates to support them.
The glazing apparatus 400 shown in FIG. 17 is one of the most effective dot point glazing apparatuses used in the dot point glazing system. As shown in FIG. 17, the dot point glazing apparatus 400 has a longitudinally extending rod 401 and a transversely extending straight arm 402 which engages the front end of the rod 401 at its center to be rotatable around the rod 401. A vertically extending straight arm 403a engages the right end of the straight arm 402 at its center to be rotatable around a longitudinally extending axis. A vertically extending straight arm 403b engages the left end of the straight arm 402 at its center to be rotatable around a longitudinally extending axis.
A longitudinally extending bolt 404a.sub.1 penetrates a hole made at the left lower corner of a glass plate 405a.sub.1 and a washer 406a.sub.1, and is screwed into a tapped hole made at upper end of the straight arm 403a. Thus, the glass plate 405a.sub.1 is connected to the dot point glazing apparatus 400 at its left lower corner. In the same way, a glass plate 405a.sub.2 disposed adjacent to and below the glass plate 405a.sub.1 is connected to the dot point glazing apparatus 400 at its left upper corner, a glass plate 405b.sub.1 disposed adjacent to and left of the glass plate 405a.sub.1 is connected to the dot point glazing apparatus 400 at its right lower corner, and a plate 405b.sub.2 disposed adjacent to and below the glass plate 405b.sub.1 is connected to the dot point glazing apparatus 400 at its right upper corner.
The glass plates 405a.sub.1, 405a.sub.2, 405b.sub.1 and 405b.sub.2 are connected to other similar dot point glazing apparatuses 400 (not shown) disposed at the other corners of the glass plates 405a.sub.1, 405a.sub.2, 405b.sub.1 and 405b.sub.2.
The rods 401 are connected to structural members which are disposed to the rear of the dot point glazing apparatuses 400 at their rear ends.
A glass screen module is formed by the glass plates 405a.sub.1, 405a.sub.2, 405b.sub.1 and 405b.sub.2. A plurality of the glass screen modules may be assembled in the vertical direction and in the transverse direction to form a glass screen.
The glazing apparatuses 400 bear the weights of the glass plates 405a.sub.1, 405a.sub.2, 405b.sub.1 and 405b.sub.2, and the wind loads acting on the glass plates 405.sub.1, 405a.sub.2, 405b.sub.1 and 405b.sub.2.
In-plane vertical relative displacements between the glass plates 405a.sub.1 and 405b.sub.1, and between the glass plates 405a.sub.2 and 405b.sub.2 are allowed by the rotation of the transverse straight arm 402, while in-plane horizontal relative displacements between the glass plates 405a.sub.1 and 405a.sub.2, and between the glass plates 405b.sub.1 and 405b.sub.2 are allowed by the rotation of the right vertical straight arm 403a, and the left vertical straight arm 403b respectively.
Thus, shear deformation of the glass screen module is allowed when an earthquake occurs, which protects the glass screen module from damage.
As will be understood from the above explanation, the dot point glazing apparatus 400 shown in FIG. 17 can effectively protect the glass screen module from damage when an earthquake occurs.
Though the dot point glazing apparatus 400 has the above merit, it has also a demerit. Once the transverse straight arm 402 has rotated, it does not readily restore to the original state. As a result, the in-plane vertical relative displacements between the glass plates 405a.sub.1 and 405b.sub.1, and between the glass plates 405a.sub.2 and 405b.sub.2, do not readily disappear after the earthquake stops. Because of this, the shear deformation of the glass screen module does not readily disappear after the earthquake stops. In order to overcome the above demerit, the upper most glass plates in the glass screen module, i.e. the glass plates 405a.sub.1, 405b.sub.1 must be suspended by spring members at the centers of their upper peripheries.